The present invention relates to a grinding wheel for producing internal profilings, especially of internally located helical teeth or gearings, and including a grinding disk that is disposed at a front end of a rod-like grinding machine arm at the respective angle of slope of the internal profiling that is to be produced, with the grinding disk being adapted to be driven by a drive shaft, which is disposed at the other end of the arm, via drive means that extends through the arm.
Various grinding wheel constructions are known for producing internal profilings. For example, German Patent 25 52 259 discloses a grinding machine arm for grinding internally located, axially extending profilings, with the grinding disk being disposed on a shaft that extends perpendicular to the longitudinal axis of the arm, is fixedly mounted in the enclosed arm, and is driven by a toothed belt. European patent application 182 158 discloses a similar grinding machine arm, the grinding disk of which, however, is driven by a shaft, which extends longitudinally in the arm, via a worm gear. Unfortunately, with this known construction it is essentially possible to grind only axially extending internal profilings or profilings that are inclined at a slight angle to the longitudinal axis.
In order to also be able to grind internally located helical teeth or gearings, grinding machine arms are known where the grinding disk is disposed at the end of a spindle that extends axially in the arm. By tilting the arm relative to the longitudinal axis of the workpiece, it is also possible to grind internal profilings that extend at an angle to the longitudinal axis of the workpiece, such as helical teeth or gearings. A grinding wheel construction of this type is disclosed, for example, in the Japanese publication 56-134 129.
If helical teeth are to be ground into workpieces that have a large axial extent but a small inner diameter, the problem results that the grinding machine arm, due to its inclination relative to the longitudinal axis of the workpiece, collides with the wall of the workpiece that is to be machined if the grinding is also to be accomplished at greater workpiece depths. To resolve this problem, two different types of construction are known.
On the one hand, it is possible to introduce the spindle into the workpiece either concentrically or at a grinding angle that is less than the angle of slope of the internal profiling that is to be ground. The difference between the angle of slope that is to be ground and the grinding angle that is formed between the longitudinal axis of the workpiece and the spindle is compensated for by a correction of the grinding disk profile. Grinding wheels of this type are disclosed in Japanese publication 57-83 320 and in German Offenlegungsschrift 36 24 472.
The second approach for resolving the aforementioned problem during the production of internally located helical teeth is to dispose the grinding disk at the front end of the rod-like grinding machine arm at the respective angle of slope of the internal profile that is to be produced. This approach is disclosed in Great Britain Patent 1 057 420, where the grinding disk is provided with exactly the profile that is to be ground on the workpiece, so that no correction of the profile is required. With this known construction, the drive for the grinding disk is effected via a shaft that extends longitudinally in the rod-like arm, and that at its front end drives the grinding disk, which is disposed on a hub-like carrier element, via a type of universal coupling.
In addition to the fact that such a drive of the grinding disk via a universal coupling does not make it possible to realize the modern high speeds of such grinding disks, the construction known from the Great Britain Patent 1 057 420 has the drawback that in order to conform the grinding disk to the respective angle of slope of the internal profiling that is to be produced, the entire grinding wheel must be disassembled in order to exchange a bearing sleeve that provides the respective tilt of the grinding disk for a similar sleeve that has a different angle of slope.
Starting from the aforementioned known construction of Great Britain Patent 1 057 420, it is an object of the present invention to provide a grinding wheel to produce internal profilings of the aforementioned type, whereby the grinding disk, which is provided with an uncorrected profile, can be adapted to the respective angle of slope of the internal profiling that is to be produced without disassembling the grinding wheel, and whereby the grinding wheel can also be driven at high speeds with little energy loss.